The invention relates to an vapor deposition of metallic materials. More particularly, the invention relates to the evaporation of materials which include elements with significantly different vapor pressures.
It is desirable to use vapor deposition to deposit materials whose components are of different vapor pressures. These include many Ti-, Co-, and Ni-based alloys.
There are a various thermal methods for evaporating solid materials in physical vapor deposition (PVD), including: resistance or induction heating; electron beam physical vapor deposition (EBPVD); laser deposition; and variations thereon. These methods may be used to evaporate and deposit metal alloys with components to have different vapor pressures. Nevertheless, such deposition can involve a variety of homogeneity problems with the deposited material (condensate).
Methods have been developed to evaporate the components of such alloys through pools comprising refractory materials. Examples are found in: Shiller, Z., Gaizig, U., and Pantser, Z., Electron-beam Technology, M. Energy, 1980, p 528; Physical Vapor Deposition, Airco Temescal, 1976, p 190; and U.S. Pat. No. 5,474,809. The '809 patent teaches a pool having a refractory component with lower vapor pressure than the components of the deposition material. The deposition material components are transported through the pool, forming a vapor stream at the pool surface. The deposition material components are continuously replaced by new material melting from the ingot. The refractory component is essentially non-consumed or is consumed in small, controllable quantities.